Contaminated materials, such as incinerator ash and soils, pose many challenges for the uranium processing industry. At uranium processing sites, incinerator ash and soils may be contaminated with different materials, including heavy metals, uranium and other radioactive materials. Uranium materials, when present in such solids, may be either uniformly distributed throughout the solids or may be concentrated in discrete sections. Removal of uranium materials from these solids is particularly difficult as, in most instances, a non-uniform distribution of uranium at low concentration levels occurs. Material treatment/separation techniques which use a mechanical separation technique (i.e. classifiers) are not equipped to separate uranium at low concentrations and, as a consequence, are not of practical use in these instances. Another drawback of mechanical separation classifiers is that these classifiers use large amounts of energy for the amount of materials separated and are therefore economically unfeasible.
Current systems used to separate uranium from solids are also expensive due to several other economic factors. The solids that are contaminated must be removed (i.e. excavated), trucked to a treatment site, treated, and then returned to the original excavation site for filling. The multiple handling steps for cleaning the solid material increases both the ultimate energy costs associated with treatment as well as the associated labor costs. Handling of contaminated solids also requires special trucking systems to prevent the solids from contaminating the trucking system and the surrounding environment due to leaks in the trucking system.
There is therefore a need to provide a method and apparatus which will allow uranium to be separated from a base solid, such as incinerator ash and/or soils, with greater efficiency than current mechanical separation techniques.
There is a further need to provide an apparatus and method which will allow the uranium to be separated economically from the base solid.
There is a further need to provide an apparatus which is easily transportable so that contaminated materials may be treated on-site, thereby minimizing handling costs.